The present invention relates to a method and apparatus for automatically processing a patient""s biological fluids such as urine, blood serum, plasma, cerebrospinal fluid and the like. In particular, the present invention provides a method to perform assays in an analyzing system having at least two analyzers each adapted to perform a number of clinical assays using various assay technologies.
Various types of tests related to patient diagnosis and therapy can be performed by analysis assays of a sample of a patient""s infections, bodily fluids or abscesses. Such patient samples are typically placed in sample vials, extracted from the vials, combined with various reagents in special reaction vessels or tubes, incubated, and analyzed to aid in treatment of the patient. In typical clinical chemical analyses, one or two assay reagents are added at separate times to a liquid sample having a known concentration, the sample-reagent combination is mixed and incubated. Interrogating measurements, turbidimetric or fluorometric or absorption readings or the like are made to ascertain end-point or rate values from which an amount of analyte may be determined using well-known calibration techniques.
Although various known clinical analyzers for chemical, immunochemical and biological testing of samples are available, analytical clinical technology is constantly challenged by increasing needs for improved sample analysis. Due to increasing demands on clinical laboratories regarding assay throughput, there continues to be a need for improvements in the overall performance of automated clinical analyzers. In particular, sample analysis continuously needs to be made more efficient in terms of reduced analyzer downtime, caused by a number of factors, which has aggravated by recent efforts to increase analyzer throughput, in particular, by linking together a number of analyzers and conveying samples between the analyzers.
An important contributor to maintaining a high throughput of automatic analyzers is the ability to quickly process a plurality of samples through a variety of different assay process and signal measurement steps. One method to achieve this feature is to serially link together analytical modules of different types, each adapted to perform a certain catalog of assays. Another is to link together two or more analyzers of the same type and to allocate incoming samples to whichever analyzer has the smallest backlog of samples to process. Alternately, incoming samples may be allocated between analyzers according to the number and availability of assay resources (reaction vessels, reagents, etc) required by the assay and duplicated on more than one analyzer. What has been overlooked, however, in the design of such prior art systems, is that throughput and/or reliability of multi-analyzer systems may be adversely affected in the event of performance failure in operational portions of either of the analyzers, analytical modules, sample entry and exit areas and/or in the conveyor means that link together two or more of the analyzers.
U.S. Pat. No. 6,261,521 discloses a sample analysis system having a plurality of analysis units placed along a main conveyor line prior to its analysis operation. The system setup includes setup of analysis units in combination with different types of reagent supply units, setup of analysis routes as to whether it is a stationary type or an automatic type, and setup of analysis items for each analysis unit as to which analysis item should be assigned to which analysis unit having which reagent supply type.
U.S. Pat. No. 6,117,392 discloses an automatic analyzing apparatus having a rack supply unit capable of containing sample racks, an analyzing unit for testing a sample sampled from a sample container contained in the sample rack, a transfer line for transferring a sample rack supplied from the rack supply unit to a position corresponding to the analyzing unit and transferring the sample rack after being sampled to an exit of the transfer line, a standby unit for keeping sample racks having a probability of being reexamined standing-by, a returning line for returning the sample rack after being sampled to an entrance side of the transfer line, and a rack collecting unit for containing sample racks not required to be reexamined.
U.S. Pat. No. 6,022,746 discloses a method for operating a multi-analyzer system by generating a list of tests to be performed by the system within a given reaction vessel. The list of tests is sorted according to the number of reaction vessels used in performing each test to be performed by the system in a given time period. A duplication percentage for the tests is determined and is compared with the sorted list of tests. Resources associated with the tests are duplicated across at least two analyzers based on the comparison of the duplication percentage with the sorted list of tests in a matter that at least one of the tests is performed by at least two of the analyzers.
U.S. Pat. No. 6,019,945 discloses a transfer mechanism for transferring a sample container holder between a conveyor line and a sampling area formed in each of several analyzers, the transfer mechanism being connectable to each one of the plurality of analyzers. At least two analyzers units are different from one other in either the types of reagent supply means, the number of analysis items that can be analyzed, the number of tests that can be processed in a unit time, or the species of samples to be processed. The at least two analysis units described above have the same attachment mechanism or the same shape thereof with respect to the conveyor line.
U.S. Pat. No. 5,972,295 discloses an automatic analyzers comprising a rack supply unit capable of containing sample racks, an analyzing unit for testing an instructed analysis item to a sample sampled from a sample container contained in the sample rack, a transfer line for transferring a sample rack supplied from the rack supply unit to a position corresponding to the analyzing unit and transferring the sample rack after being sampled to an exit of the transfer line, a standby unit for keeping sample racks having a probability of being reexamined stand-by, a returning line for returning the sample rack after being sampled to an entrance side of the transfer line, and a rack collecting unit for containing sample racks not required to be reexamined.
U.S. Pat. No. 5,966,309 discloses an automated apparatus for subjecting samples to one or more selected test procedures at one or more test stations comprising a conveyor line for transporting samples contained in uniquely labeled containers, said line having at least two lanes for routing said containers to one or more selectable test stations, at least one of said lanes being a transport lane and at least one of said lanes being a queue line, and having a container interface device for transferring containers to said testing device from the queue lane and back again onto said queue lane.
U.S. Pat. No. 5,902,549 discloses a plurality of analyzer units for serum, a plurality of analyzer units for blood plasma, and a plurality of analyzer units for urine are arranged along a main transfer line for transferring a sample rack from a rack providing portion to a rack storage portion. A reagent bottle for inspecting liver function is contained in each reagent delivery mechanism of two analyzer units among the plurality of analyzer units for serum. When the reagent for inspecting liver function in one of the two analyzer units is to be short, analysis for the liver function analysis item in the samples can be continued by transferring a sample rack from the rack providing portion to the other analyzer unit.
U.S. Pat. No. 5,380,488 discloses a container feeding system which includes a feed stocker for stocking racks holding containers, one or more sampling feeders connected to the downstream side of the feed stocker, and one or more analyzers for withdrawing samples from containers which are moved to sampling positions in an interlocked relation to the sampling feeder or feeders. One or more coupling feeders are connected to the respective downstream sides of the sampling feeder or feeders, and a treated container stocker is connected to the most downstream side of the coupling feeder or feeders. The individual components are provided as respective units. The number of sampling feeders and coupling feeders connected thereto can be increased or reduced, and in correspondence therewith so can the number of analyzers disposed along a rack feeding line. The rack feeding path can thus be readily increased and reduced, as desired, to meet the scale of the delivery side. Likewise, the control mechanism for controlling the feeding of containers with selective priority is also greatly simplified.
U.S. Pat. No. 5,087,423 discloses a plurality of analyzing modules, a plurality of analyzing routes and at least one bypass route bypassing at least one analyzing module are arranged. Each analyzing module is capable of analyzing samples with respect to one or more items, and samples successively supplied from the introduction sides of the modules are selectively delivered into each module in accordance with the possible analyzing items of each module and the analyzing items of the samples to be analyzed. The sample cup can pass the module via a bypass or can be returned to the introduction side of the module via a bypass, in accordance with the items to be analyzed, the effective distribution of the sample cups can be performed.
From this discussion of the art state in automated clinical analyzers, it may be seen that while progress has been made toward increasing processing efficiency, there remains an unmet need for a method for operating a multi-analyzer system in a way that enhances the reliability of multi-analyzer systems. In particular, little progress has been made toward increasing the reliability of operation of a multi-analyzer system by providing back-up operational capability in the event of performance failure in various operating portions of any of the analyzers and/or in the conveying means that link together the analyzers.
The principal object of the invention is to provide a method for using a clinical analyzer system where at least two automatic clinical analyzers are linked together, that is a multi-analyzer system having two or more analyzers connected together in a manner that ensures system throughput and/or reliability in the event of machine or performance failure in operating portions of either of the analyzers and/or in the connecting means that link together the analyzers. Each analyzer includes a circular rotatable assay reaction carousel for holding reaction vessels and providing stepwise movements in a circular direction, the stepwise movements being separated by stationary dwell times, during which dwell times an assay device may operate on an assay mixture contained within a reaction vessel. A multi-analyzer system like those on which the present invention may be performed typically has a plurality of conventional assay operation stations at which are positioned individual assay devices, such as sensors, reagent add stations, mixing stations, separation stations, and the like.
In an exemplary embodiment of the present invention, a key feature is that at least two automatic clinical analyzers are linked together by a bi-directional shuttle, the bi-directional shuttle adapted to move only a single sample rack or only a similar device between said analyzers. The two analyzers are essentially machine-wise identical to one another except that the menu of assays capable of being performed on the individual analyzers may be optionally and selectively different; i. e., both analyzers are equipped with physically identical sample handling, reagent storage and sample processing and assaying devices, etc. However, both analyzers may be equipped with a slightly different inventory of reagents stored on-board each so that the analyzers are initially capable of performing a slightly different menu of assays. In a stand-alone mode, each analyzer has an independently operable bi-directional incoming and outgoing automated sample rack transport system, so that samples to be tested may be placed onto an analyzer, automatically subjected to the requested assay protocols, and returned to an inventory of samples finally tested. However, when the machines are linked together by a bi-directional shuttle, the bi-directional incoming and outgoing sample rack transport system of a first one of the two analyzers is automatically converted into a one-way incoming sample rack transport system adapted to receive all sample racks carrying sample tubes to be analyzer by either analyzer. In a similar manner, the incoming sample tube transport system of a second of the two analyzers is automatically converted into a one-way outgoing transport system adapted to dispose of all sample racks having sample tubes with samples finally tested by either analyzer. Because the bi-directional shuttle is adapted to move only a single sample rack or similar device between analyzers, in the event that one of the two analyzers experiences an operating failure or in the event that the bi-directional shuttle experiences an operating failure, the analyzer system may automatically revert to a single analyzer system employing only the operational analyzer and samples may be supplied only to and analyzed only by the operational analyzer.